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3 votes
Which ordered pairs make both inequalities true? Check all that apply.

y < 5x + 2

y >= 1/2x + 1

These are the choices....
#1. (–3, 2)

#2. (–1, 3)

#3. (0, 2)

#4. (1, 2)
#5. (2, –1)
#6. (2, 2)

User Jmkiley
by
6.6k points

2 Answers

6 votes

we have


y < 5x + 2 -------> inequality
1
y \geq (1)/(2)x + 1 -------> inequality
2

using a graph tool

see the the attached figure N
1

the solution of the system is the shaded area


case 1) (-3, 2)

This point satisfies the inequality
2 but does not satisfy the inequality
1.

therefore

it is not a solution of the system

see the attached figure N
2


inequality
1


(-3,2)\\ x=-3\\ y=2


2 < 5*(-3) + 2


2 < -13 -----> is not true

inequality
2


(-3,2)\\ x=-3\\ y=2


2 \geq (1)/(2)*(-3) + 1


2 \geq -(1)/(2) -----> is true


case 2) (-1, 3)

This point satisfies the inequality
2 but does not satisfy the inequality
1.

therefore

it is not a solution of the system

see the attached figure N
2


inequality
1


(-1, 3)\\ x=-1\\ y=3


3 < 5*(-1) + 2


3 < -3 -----> is not true

inequality
2


(-1, 3)\\ x=-1\\ y=3


3 \geq (1)/(2)*(-1) + 1


3 \geq (1)/(2) -----> is true


case 3) (0, 2)

This point satisfies the inequality
2 but does not satisfy the inequality
1.

therefore

it is not a solution of the system

see the attached figure N
2


inequality
1


(0, 2)\\ x=0\\ y=2


2 < 5*(0) + 2


2 < 2 -----> is not true

inequality
2


(0, 2)\\ x=0\\ y=2


2 \geq (1)/(2)*(0) + 1


2 \geq 1 -----> is true


case 4) (1, 2)

This point satisfies the inequality
2 and satisfies the inequality
1.

therefore

it is a solution of the system

see the attached figure N
2


inequality
1


(1, 2)\\ x=1\\ y=2


2 < 5*(1) + 2


2 < 7 -----> is true

inequality
2


(1, 2)\\ x=1\\ y=2


2 \geq (1)/(2)*(1) + 1


2 \geq (3)/(2) -----> is true


case 5) (2,-1)

This point satisfies the inequality
1 but does not satisfy the inequality
2.

therefore

it not a solution of the system

see the attached figure N
2


inequality
1


(2, -1)\\ x=2\\ y=-1


-1 < 5*(2) + 2


-1 < 12 -----> is true

inequality
2


(2, -1)\\ x=2\\ y=-1


-1 \geq (1)/(2)*(2) + 1


-1 \geq 2 -----> is not true


case 6) (2, 2)

This point satisfies the inequality
1 and satisfies the inequality
2.

therefore

it is a solution of the system

see the attached figure N
2


inequality
1


(2, 2)\\ x=2\\ y=2


2 < 5*(2) + 2


2 < 12 -----> is true

inequality
2


(2, 2)\\ x=2\\ y=2


2 \geq (1)/(2)*(2) + 1


2 \geq 2 -----> is true

therefore

the answer is


case 4) (1, 2)\\ case 6) (2, 2)

Which ordered pairs make both inequalities true? Check all that apply. y < 5x + 2 y-example-1
Which ordered pairs make both inequalities true? Check all that apply. y < 5x + 2 y-example-2
User Daan Wilmer
by
7.3k points
1 vote
All others did not satisfy the inequality simultaneously except #4 and #6
For #4:
2 < 5(1) + 2 i.e. 2 < 7 (true)
2 >= 1/2(1) + 1 i.e. 2 >= 3/2 (true)
For #6
2 < 5(2) + 2 i.e. 2 < 12 (true)
2 >= 1/2(2) + 1 i.e. 2 >= 2

User Ryan Mohr
by
7.3k points